Cikgu Rumaizah

[FORM 5] Chapter 1: TRANSPORT 1.1 - 1.3

2012-01-11T17:51:00.000-08:00

The first chapter in form five. The title of this chapter is transportation. For this time I just uploaded subtopic 1.1 to 1.3 only. The next subtopics will be uploaded once completed. Please get the note here. Read and try to understand. For the video version I will try to embed it directly into the blog. Have fun learning!

NOTES 1.1 - 1.3

Chapter 1: Transport (1.1 - 1.3)

View more presentations from maieymuhamad

THE CIRCULATORY SYSTEM

CONDUCTING SYSTEM OF HEART

THE MECHANISM OF BLOOD CLOT (HAEMOSTASIS)

Welcome 2012!

2012-01-10T20:32:00.000-08:00

Almost 6 months didn’t write and the blog seems cobwebbed. In this early new year I were given a task to teach form 5 students of two biological classes. This year is also assigned as s/u PBS and it was still unclear how the implementation is and just waiting and waiting for instructions from the superior. To students, I’ll give the best for you and make us proud in SPM later. God willing..

Chronic Rhinitis and Post-Nasal Drip

2011-07-19T09:32:00.000-07:00

I just came back from hospital and i had been diagnosed a chronic disorder named chronic rhinitis. it is a condition where you'll get inflamed once you get contact with allergens and it worsened by infection with bacteria or viruses when the fluid (mucus) are blocked from drained through nasal passage. What is chronic rhinitis??

I just copied and paste from this source:
http://www.medicinenet.com/chronic_rhinitis/article.htm

What is the purpose of the nose?

The purpose of the nose is to warm, clean, and humidify the air you breathe as well as help you to smell and taste. A normal person will produce about two quarts of fluid each day (mucus), which aids in keeping the respiratory tract clean and moist. Tiny microscopic hairs (cilia) line the surfaces of the nasal cavity, helping to brush away particles. Eventually the mucus blanket is moved to the back of the throat where it is unconsciously swallowed. This entire process is closely regulated by several body systems.

Structurally, the nose is separated into two passageways (left and right nostrils) by a structure called the septum. Protruding into each breathing passage are bony projections, called turbinates, which help to increase the surface area of the inside of the nose. There are three turbinates on each side of the nose (inferior or lower turbinates, middle turbinates, superior or upper turbinates). The sinuses are four paired, air-filled chambers which empty into the nasal cavity. Their purpose is not really known, but may help to lighten the skull, reducing its weight.

What are rhinitis and post-nasal drip?

Rhinitis is a very common condition and has many different causes. Basically, rhinitis may be defined as inflammation of the inner lining of the nose. More specifically speaking, it may be defined by the presence of one or more of the following symptoms:

Rhinorrhea (runny nose)
Nasal itching
Nasal congestion
Sneezing

Post-nasal drip is mucus accumulation in the back of the nose and throat leading to, or giving the sensation of, mucus dripping downward from the back of the nose. One of the most common characteristics of chronic rhinitis is post-nasal drip. Post-nasal drip may lead to chronic sore throat or chronic cough. Post-nasal drip can be caused by excessive or thick secretions, or impairment in the normal clearance of mucus from the nose and throat.

What causes rhinitis?

Rhinitis has many possible causes. Rhinitis can be either acute or chronic.

Allergic rhinitis is a very common cause of rhinitis. It is caused by allergies and is characterized by an itchy/runny nose, sneezing, and nasal congestion. Other allergic symptoms include:

itchy ears and throat,
Eustachian tube problems (the tube connecting the inner ear to the back of the throat),
red/watery eyes,
cough,
fatigue/loss of concentration/lack of energy from loss of sleep, and
headaches or facial tenderness.

People with allergic rhinitis also have a higher incidence of asthma and eczema, which are also mainly allergic in origin.

Seasonal allergic rhinitis (hay fever) is usually caused by pollen in the air, and sensitive patients have symptoms during peak times during the year.

Perennial allergic rhinitis, a type of chronic rhinitis is a year-round problem, and is often caused by indoor allergens (particles that cause allergies), such as dust and animal dander in addition to pollens that may exist at the time. Symptoms tend to occur regardless of the time of the year.

Is rhinitis always related to allergies?

No, rhinitis may have many causes other than allergies. Some of these other types of rhinitis are listed below.

Non-allergic rhinitis occurs in those patients in whom an allergic or other causes of rhinitis cannot be identified. Non-allergic rhinitis may be further divided into three types;

vasomotor rhinitis,
gustatory rhinitis, and
non-allergic rhinitis with nasal eosinophilia syndrome (NARES).

These conditions may not have the other allergic manifestations such as, itchy and runny eyes and are also more persistent and less seasonal.

Vasomotor rhinitis is thought to occur because of abnormal regulation of nasal blood flow and may be induced by temperature fluctuations in the environment such as, cold or dry air, or irritants such as:
- air pollution,
- smog,
- tobacco smoke,
- car exhaust, or
- strong odors such as, detergents or fragrances.
Gustatory rhinitis may presents predominantly as runny nose (rhinorrhea) related to consumption of hot or spicy food.
Non-allergic rhinitis with nasal eosinophilia syndrome (NARES) is characterized by a clear nasal discharge. The nasal discharge is found to have eosinophils (allergic cell type), although the patient may not have any other evidence of allergy by skin testing or history or symptoms.

Occupational rhinitis may arise from exposure to irritants at a person's workplace with improvement of symptoms after the person leaves the workplace.

Other causes of rhinitis may be related to:

pregnancy,
certain medications (oral contraceptives,
some blood pressure medications,
some anxiety medications,
some erectile dysfunction medications,
and some anti-inflammatory medications), or
some nasal structural abnormalities (deviated septum, perforated septum, tumors, nasal polyps, or foreign bodies).

Infections, mostly viral, are a common cause of rhinitis. Viral rhinitis is usually not chronic and may resolve by itself.

Sometimes rhinitis may be related to other generalized medical conditions such as:

acid reflux disease (GERD),
Wegener's granulomatosis,
sarcoidosis,
cystic fibrosis, and
other less common conditions.

How can chronic rhinitis and post-nasal drip be treated?

The treatment is generally directed towards the underlying cause.

Identifying and avoiding allergens

An allergy is an exaggerated "normal body" inflammatory response to an outside substance. These substances that cause allergies are called allergens, and typically include:

pollen,
mold,
animal dander (cats and dogs),
house dust,
dust mites and cockroaches, and
some foods.

The best treatment is avoidance of these allergens, but in many cases this may be very difficult if not impossible. Some helpful suggestions include:

Use a pollen mask when mowing the grass or cleaning the house;
install an air purifier or at least change the air filters monthly in heating and air conditioning systems;
use cotton or synthetic materials such as Dacron in pillows and bedding;
enclose mattress in plastic;
consider using a humidifier;
keep windows closed during high pollen times;
eliminate house plants; and bathe pets frequently or even give away dander-producing pets.

Avoidance of nasal irritants: Nasal irritants usually do not lead to the typical immune response seen with classical allergies, but nevertheless they can mimic or make allergies worse, as in vasomotor rhinitis. Examples of these irritants include cigarette smoke, perfume, aerosol sprays, smoke, smog and car exhaust.

Identifying the possible allergens may be just as hard as avoiding them. In some, this may be identified by a very careful history taken by their physician. Details of the patient's possible exposure to allergens or irritant at home or the workplace may give some clues. In others, even a very detailed history may not reveal a possible trigger. Therefore, a consultation with an allergy specialist (allergy and immunologist) may be prudent. The allergy doctor may perform some simple skin tests to try to identify common environmental allergies.

What medications can be used to treat rhinitis and post-nasal drip?

In addition to measures noted above, medications may also be used for the treatment of rhinitis and post-nasal drip.

For allergic rhinitis and post-nasal drip many medications are used.

Steroid nasal sprays

The experts recommend using intra-nasal glucocorticoids (steroid sprays applied directly into the nose) as the first line of treatment. Steroids are known to be potent anti-inflammatory and anti-allergic agents and they are known to relieve most of the associated symptoms of runny and itchy nose, nasal congestion, sneezing, and post-nasal drip.

Their use must be monitored and tapered by the prescribing physician as long-term use may have significant side effects. Examples of the nasal steroids include:

beclomethasone (Beconase),
flunisolide (Nasarel),
budesonide (Rhinocort),
fluticasone propionate (Flonase),
mometasone furoate (Nasonex), and
fluticasone furoate (Veramyst).

These are generally used once or twice daily. It is recommended to tilt the head forward during the administration to avoid from spraying the back of the throat instead of the nose.

Oral steroids

These drugs [prednisone, methylprednisolone (Medrol), hydrocortisone (Hydrocortone, Cortef)] are highly effective in allergic patients; however there is a potential for serious side effects when used for extended periods. They are best used for the short-term management of allergic problems, and a physician must always monitor their use. These are reserved only for very severe cases that do not respond to the usual treatment with nasal steroids and antihistamines.

Antihistamines

Allergy medications, such as antihistamines, are also frequently used to allergic rhinitis and post-nasal drip. These are generally used as the second line of treatment after the nasal steroids or in combination with them. Histamines are naturally occurring chemicals released in response to an exposure to an allergen, which are responsible for the congestion, sneezing, and runny nose typical of an allergic reaction. Antihistamines are drugs that block the histamine reaction. These medications work best when given prior to exposure.

Antihistamines can be divided into two groups:

Sedating, or first generation [diphenhydramine (Benadryl), chlorpheniramine (Chlor-Trimeton), clemastine (Tavist)]. Sedating antihistamines should be avoided in those patients who need to drive or use dangerous equipment.
Non-sedating or second generation [loratadine (Claritin), cetirizine (Zyrtec)]. Non-sedating antihistamines can have serious drug interactions. Most of these are found over the counter.

There is also a nasal antihistamine preparation that has been shown to be very effective in treating allergic rhinitis, called azelastine nasal (Astelin).

Decongestant sprays

Examples of decongestant sprays include:

oxymetazoline (Afrin), and
phenylephrine (Neo-Synephrine)

Decongestant sprays quickly reduce swelling of nasal tissues by shrinking the blood vessels. They improve breathing and drainage over the short-term. Unfortunately, if they are used for more than a few days they can become highly addictive (rhinitis medicamentosa). Long-term use can lead to serious damage. Therefore, their use should limited to only 3 to 7 days.

Oral decongestants

Oral decongestants temporarily reduce swelling of sinus and nasal tissues leading to an improvement of breathing and a decrease in obstruction. They may also stimulate the heart and raise the blood pressure and should be avoided by patients who have high blood pressure, heart irregularities, glaucoma, thyroid problems, or difficulty in urination. The most common decongestant is pseudoephedrine (Sudafed).

Cromolyn sodium (Nasalcrom)

Cromolyn sodium (Nasalcrom) is a spray helps to stabilize allergy cells (mast cells) by preventing release of allergy mediators, like histamine. They are most effective if used before the start of allergy season or prior to exposure to a known allergen.

Montelukast (Singulair)

Montelukast (Singulair) is an agent that acts similar to antihistamine, although it is involved in another pathway in allergic response. It has been shown to be less beneficial than the steroid nasal sprays, but equally as effective as some of the antihistamines. It may be useful in patients who do not wish to use nasal sprays or those who have co-existing asthma.

Ipratropium (Atrovent nasal)

Ipratropium (Atrovent nasal) is used as a nasal spray and helps to control nasal drainage mediated by neural pathways. It will not treat an allergy, but it does decrease nasal drainage.

Mucus thinning agents

Mucus thinning agents are utilized to make secretions thinner and less sticky. They help to prevent pooling of secretions in the back of the nose and throat where they often cause choking. The thinner secretions pass more easily. Guaifenesin (Humibid, Fenesin, Organidin) is a commonly used formulation. If a rash develops or there is swelling of the salivary glands, they should be discontinued. Inadequate fluid intake will also thicken secretions. Increasing the amount of water consumed, and eliminating caffeine from the diet and the use of diuretics are also helpful.

Allergy shots (Immunotherapy)

Allergy shots interfere with the allergic response. After identification of an allergen, small amounts are given back to the sensitive patient. Over time the patient will develop blocking antibodies to the allergen, and they become less sensitive and less reactive to the substance causing allergic symptoms.

Combinations

These drugs are made up of one or more anti-allergy medications. They are usually a combination of an antihistamine and a decongestant. Other common combinations include mucus thinning agents, anti-cough agents, aspirin, ibuprofen (Advil), or acetaminophen (Tylenol). They help to simplify dosing and often will work either together for even more benefit or have counteracting side effects that eliminate or reduce total side effects.

Terminology

Acute rhinitis: Inflammation of the nose that occurs for only a few days. Typically this is caused by a virus ("a cold"); if it goes on beyond a week then it is probably a bacterial infection.

Allergens: Normally harmless substances which cause an exaggerated allergic reaction (inflammatory response) in sensitive people.

Allergic rhinitis: Medical term for hay fever, a condition due to allergy that mimics a chronic cold. (Hay fever is a misnomer since hay is not a usual cause of this problem and there is no fever). Many substances cause the allergic symptoms in hay fever. Allergic rhinitis is the correct term for this allergic reaction. (Rhinitis means "irritation of the nose" and is a derivative of Rhino, meaning "nose.") Symptoms include nasal congestion, a clear runny nose, sneezing, nose and eye itching, eye redness, and tearing of the eyes. Post-nasal dripping of clear mucus frequently causes a cough. Loss of smell is common, and loss of taste occurs occasionally. Nose bleeding may occur if the condition is severe.

Chronic rhinitis: inflammation of the nose that goes on for weeks to months which is different from "a cold", and may be caused by allergy, nasal irritants, or structural or physiological problems.

Hay fever: A seasonal allergy to airborne particles characterized by runny/itchy nose and eyes, sneezing, itchy throat, excess mucus, and nasal congestion. It is a misnomer because it is not caused by hay and it does not produce a fever.

Non-allergic rhinitis: Inflammatory condition of the nose without an obvious allergy as the cause.

Post nasal drip: Mucous accumulation in the back of the nose and throat leading to or giving the sensation of mucus dripping downward from the back of the nose.

Summer cold: Similar to hay fever. Summer cold is also a misnomer because it is not caused by a virus.

Vasomotor rhinitis: Similar to non-allergic rhinitis, thought to be mediated by an abnormal neuronal control of the blood vessels supplying the nose.

Mechanism of Enzyme Action [Lock and Key theory]

2011-05-16T04:44:00.000-07:00

The basic mechanism by which enzymes catalyze chemical reactions begins with the binding of the substrate (or substrates) to the active site on the enzyme. The active site is the specific region of the enzyme which combines with the substrate. The binding of the substrate to the enzyme causes changes in the distribution of electrons in the chemical bonds of the substrate and ultimately causes the reactions that lead to the formation of products. The products are released from the enzyme surface to regenerate the enzyme for another reaction cycle.

The active site has a unique geometric shape that is complementary to the geometric shape of a substrate molecule, similar to the fit of puzzle pieces. This means that enzymes specifically react with only one or a very few similar compounds.

Lock and Key Theory:

The specific action of an enzyme with a single substrate can be explained using a Lock and Key analogy first postulated in 1894 by Emil Fischer. In this analogy, the lock is the enzyme and the key is the substrate. Only the correctly sized key (substrate) fits into the key hole (active site) of the lock (enzyme).

Smaller keys, larger keys, or incorrectly positioned teeth on keys (incorrectly shaped or sized substrate molecules) do not fit into the lock (enzyme). Only the correctly shaped key opens a particular lock. Watch the video below for better understanding on mechanism of enzyme action.

Meiosis

2011-05-16T04:15:00.000-07:00

Meiosis begins with Interphase I. During this phase there is a duplication genetic material, DNA replication. Cells go from being 2N, 2C (N= chromosome content, C = DNA content) to 2N, 4C. Cells remain in this active phase 75% of the time. The chromatin remains in a nuclear envelope while a pair of centrioles lies inside a centrosome.

During Prophase I, the chromatin condenses into chromosomes, the nuclear envelope disappears, and a spindle apparatus begins to form. Each chromosome consists of a pair of chromatids connected by a centromere. Cells are now 4N, 4C. The major occurrence in this phase is the coupling of these homologous chromosomes. Two double-stranded chromosomes form a four-stranded tetrad. In some cases, there is crossing-over of the two middle strands, at a site called the chiasma, such that there is genetic recombination. This process is extremely important for creating genetic diversity.

In Metaphase I, the tetrads line up on the "equator" of the cell. The centrosome has replicated and one has moved to each pole. Microtubules that extend out of each centrosome attach to kinetochores in the center of each side of the tetrads that have lined up on the equator.

5.2

View more presentations from maieymuhamad.

Mitosis

2011-05-16T03:35:00.000-07:00

Mitosis is a process of cell division which results in the production of two daughter cells from a single parent cell. The daughter cells are identical to one another and to the original parent cell.

In a typical animal cell, mitosis can be divided into four principals stages:

Prophase: The chromatin, diffuse in interphase, condenses into chromosomes. Each chromosome has duplicated and now consists of two sister chromatids. At the end of prophase, the nuclear envelope breaks down into vesicles.
Metaphase: The chromosomes align at the equitorial plate and are held in place by microtubules attached to the mitotic spindle and to part of the centromere.
Anaphase: The centromeres divide. Sister chromatids separate and move toward the corresponding poles.
Telophase: Daughter chromosomes arrive at the poles and the microtubules disappear. The condensed chromatin expands and the nuclear envelope reappears. The cytoplasm divides, the cell membrane pinches inward ultimately producing two daughter cells (phase: Cytokinesis).

5.1 Mitosis

View more presentations from maieymuhamad.

Chemical Composition of The Cell

2011-04-02T21:25:00.000-07:00

Huhh..lama tak menulis..

Next week masuk chapter 4. lot of things to study..it's like a biochemistry (a killer subject that might kill me 5 yrs ago.hmm)..

just to share...

Plasma membrane is formed of the following chemical components:

1. Lipids: The bulk of plasma membrane is formed of lipids. The main lipid component of the plasma membrane is phospholipid. About 5 important phospholipids are seen. Of these lecithin is the most abundantly seen phospholipid. Cholesterol and cephalin are also found. Some lipids are triglycerides. The lipids of the cell membrane are polar lipids. They contain hydrophilic heads and hydrophobic tails.

2. Proteins: The proteins of plasma membrane have high molecular weight. Three different classes of proteins occur in the plasma membrane. They are structural proteins, carrier proteins and enzymes. The structural proteins form the 'back bone' of the cell membrane. The carrier proteins are involved in active transport. The enzymes include ATP ase, phosphatase, hexokinase, RNA ase and esterase.

3. Carbohydrates: They form a cell coat around the plasma membrane. Hexose, hexosamine, fucose and sialic acid are the important carbohydrates found in the plasma membrane of RBC. Plasma membrane of Amoeba proteus contains a large amount of polysaccharides.

4. Water: The cell membrane also contains water.

chapter 2: CELL STRUCTURE AND CELL ORGANIZATION

2011-01-27T06:46:00.000-08:00

You can download your ch 2 notes here. Any problem, we'll discuss in class.

chapter 1: INTRODUCTION TO BIOLOGY

2011-01-27T06:40:00.000-08:00

Hi all, you can download your notes (chapter 1) here.

4 Mulia: Scheme for year end examination Biology (JPS)

2010-11-18T02:48:00.000-08:00

Hi all,

you can download answer scheme here.... :)

Can soy milk replace milk?

2010-11-18T01:27:00.000-08:00

Soy milk is often the preferred choice for individuals who do not consume animal products or who cannot tolerate the lactose in cow's milk. Soy milk can be used in a variety of ways and in many different resipes. It should be substituted at a ratio of one-to-one with cow's milk making it an easy switch for anything from coffee beverages to casserole recipes.

The major difference between soymilk and "regular" milk (predominantly cow's milk in the United States; goat and sheep's milk are other options) is that one is derived from a plant and the other from an animal. Although ethical, hypothetical, or debatable issues frequently arise when discussing this subject, this answer is going to deal strictly with the nutritional differences between these two kinds of milk.

What's most commonly referred to as milk is cow's milk, which is a product of the mammary gland. As with all other animal-based foods, it's a complete protein; that is, it supplies people with all the necessary amino acids to form proteins. All cow's milk contain 8 grams of protein and 12 grams of carbohydrate per cup. Cow's milk is a rich source of other nutrients as well. One cup provides adults with 30 percent of their daily calcium needs and about 50 percent of their vitamin B₁₂ and riboflavin requirements. Often it's fortified with vitamin D to facilitate the absorption of calcium. Vitamin A is usually added to milk as well. Depending on the selection, cow's milk can have a significant amount of fat. (See the chart at the end of the answer for a comparison of the fat content of some varieties of milk.)

Lactose, the primary carbohydrate in cow's milk, poses a digestive problem for some people. These folks are deficient in the lactase enzyme that's needed to break down this milk sugar, causing gas, bloating, and diarrhea after consuming some forms of dairy products. The solution is to purchase products with the lactose already broken down, to take the enzyme in the form of a pill or drops, or to find a substitute for these foods.

Soymilk is not technically a milk, but a beverage made from soybeans. It is the liquid that remains after soybeans are soaked, finely ground, and then strained. Since it doesn't contain any lactose, soymilk is suitable for lactose intolerant folks. It's also a popular cow's milk substitute for vegetarians since it's based on a plant source (others include rice, oat, almond, coconut, and potato milk).

Soy foods are the only plant-based complete proteins. One cup of unfortified soymilk contains almost 7 grams of protein, 4 grams of carbohydrate, 4½ grams of fat, and no cholesterol. Although soymilk supplies some B vitamins, it's not a good source of B₁₂, nor does it provide a significant amount of calcium. Since many people substitute soy beverages for cow's milk, manufacturers have offered fortified versions. These varieties may include calcium and vitamins E, B₁₂, and D, among other nutrients. If you choose soymilk, read labels carefully to be sure you're getting enough of these important nutrients.

Soymilk may help some people reduce their risk for heart disease. Soy naturally contains isoflavones, plant chemicals that help lower LDL ("bad" cholesterol) if taken as part of a "heart healthy" eating plan. The recommendation is to take in about 25 grams of soy protein per day. One cup of soymilk has about 7 - 10 grams of protein, depending on the brand. Women who have had breast cancer may want to limit their intake of soy protein, as some studies have pointed to possible harm from consuming excess soy in this group.

All in all, what you choose to drink is really a matter of personal preference and your health objectives. You may find this chart helpful in comparing the nutritional qualities between cow's milk and soymilk [per 1 cup (8 oz.) serving]:

Product	Calories	Fat(g)	%fat	Calcium(mg)*	Vit. B₁₂(mcg)*
Cow's Milk:
Whole milk	150	8	48	290	.87
Reduced fat (2%)	120	5	38	297	.89
Low fat (1%)	100	3	27	300	.90
Skim	85	0.4	4	302	.93
Soy:
Unfortified	79	4.5	51	10	0
Fortified **	130	4	28	200	1.0

*RDA (men and women) for: Calcium: 1,000 - 1,300 milligrams/day (depending upon age) Vitamin B₁₂: 2.0 micrograms/day

source: http://www.goaskalice.columbia.edu/1861.html

More info?? http://www.waset.org/journals/waset/v57/v57-76.pdf

Rhinorrhea

2010-11-05T07:58:00.001-07:00

"Rhinorrhea" is not a rhinoceros. Rhinorrhea is commonly referred to as runny nose, consists of a significant amount of nasal fluid. It is a symptom of the common cold and of allergies (hay fever). The term is a combination of the Greek words "rhinos" meaning "of the nose" and "-rrhea" meaning "discharge or flow".

while

"Stuffy nose" is a term often used to refer to obstruction to the flow of air in and out of the nose. Both of these conditions are associated with inflammation and swelling (congestion) of the inner lining of the nasal passages and sinuses. A viral infection (the common cold) is the most common cause of a stuffy and/or runny nose, but allergies, influenza, and sinus infections also may cause these symptoms.

Less commonly, anatomical obstructions (e.g. a deviated nasal septum, foreign bodies) may lead to nasal congestion. Other causes of a stuffy or runny nose include environmental factors, hormonal changes, and some medications. Rarely, tumors of the nasal passages or chronic medical conditions may be the cause of a stuffy or runny nose.

CAUSES

Rhinorrhea may be due to allergic conditions such as hay fever or foreign materials within the nostril. Bacterial or viral infections such as the common cold, influenza or sinusitis may also be accompanied by a runny nose. Nasal discharges may also be present in cases of vasomotor, a non-infectious and non-allergenic condition.

Head injuriesmay also cause excess nasal discharges. Basilar skull fracture may result in cerebrospinal fluid rhinorrhea.

Environmental causes include contact with strong smelling substances such as disulphide compounds found in onions and garlic, both of the genus Allium. CS gas, which provides an especially intense pepper-like odor, also results in this symptom. This phenomenon is caused by the same mechanism that causes a runny nose when crying: tears drain through the inner corner through the nasolacrimal duct, and finally into the nasal cacity, where they manifest as a runny nose. Spicy food can also be to blame, as well as exposure to cold air, both of which can cause tearing.

Additional factors are temperature related: if the climate is dry or the air in one's vicinity becomes especially dry, the nose reacts by producing more mucus. The nose also tends to run when one is exposed to very cold temperatures; this is because air in the nose is warmer than outside air and a steam-like effect is brought on inside the nose; water drops then condense, mix with mucus, and run out of the nose.

Baby Colds, cough and flu

Every year a new round of viruses hits, and babies, with their untested immune systems, are prime targets. But there are plenty of ways to help babies avoid colds and the flu – and to make your baby more comfortable and happy if he develops a cough, congestion, or runny nose.

One reason that babies get a lot of colds is that their immune systems are immature, making them more vulnerable to illness. Also, your child can develop immunity to only one of the more than 200 different viruses that cause the common cold at a time. Think of all the colds you've had in your lifetime. Your baby would have to get all of those — and more — to be immune to all cold viruses.

Why does my baby get so many colds?

As your baby grows, he's likely to be exploring a lot and touching (and licking!) everything, so it's easy for him to pick up a cold virus on his hands. Then all he has to do is put his fingers in his mouth or nose or rub his eyes, and the virus will get a chance to set up shop.

Your baby may get sick more often during the fall and winter months because cold air and indoor heating dry out his nasal membranes, making it easier for a cold virus to get a foothold there. He also spends more time during cold weather cooped up indoors, where viruses can spread more easily from one person to another.

Most children average between six and ten colds per year. In families with children in daycare or school, the number of colds can reach 12 per year! (The average adult gets two to four colds annually.)

How can I tell if he has a cold and not the flu or some other illness, or even allergies?

It can be tricky. If your baby has a cold, he might have a runny nose with clear mucus that may thicken and turn gray or yellow or green over the next week or so. He might have a cough or a low-grade fever.

If your baby is running a fever, watch him when his fever comes down. If he plays and eats normally (or almost normally — he might eat a bit less and drag a little), then it's probably a cold. If he acts ill even when his temperature drops, though, he may have something more serious than a cold. Also, a flu or other illness is more likely to have an abrupt onset, and is more likely to be accompanied by diarrhoea or vomitting. On the other hand, if congestion or coughing shows up before any fever, it's more likely that your child has a cold.

Itchy, watery eyes and nose are hallmarks of an allergy, as are repeated sneezing attacks and itchy skin that lasts for weeks or months. Also, the mucus coming out of your baby's nose will continue to run clear, rather than thickening and turning yellow or green as it tends to in children with colds. Allergies won't cause your child to run a fever, and they tend to show up in the spring, summer, and early fall.

[Shared to all parents and parents to be..]

CHAPTER 8: Dynamic Ecosystem

2010-10-15T05:03:00.000-07:00

DYNAMIC ECOSYSTEM?

Click here for details (8.4)

Click here for details (8.5)

CHAPTER 7: Respiration

2010-10-09T03:22:00.000-07:00

Respiration may refer to:

Cellular respiration, the process in which nutrients are converted into useful energy in a cell
Respiration (physiology) and Breathing, the physiological process that enables animals to exchange carbon dioxide, the primary product of cellular respiration, for fresh air.
Anaerobic respiration, cellular respiration without oxygen
Aquatic respiration, the process of animals extracting oxygen from water
Carbon respiration, a concept used in calculating carbon (as CO₂) flux occurring in the atmosphere
Ecosystem respiration, measure of gross carbon dioxide production by all organisms in an ecosystem
Root respiration, exchange of gases between plant roots and the atmosphere
Maintenance respiration, the amount of cellular respiration required for an organism to maintain itself in a constant state.

definition by: http://en.wikipedia.org/wiki/Respiration

click here for subtopics: 7.1, 7.2, 7.3, 7.4

CHAPTER 5: Cell Division

2010-10-09T02:40:00.000-07:00

Cell division is the process by which a parent cell divides into two or more daughter cells. Cell division is usually a small segment of a larger cell cycle. This type of cell division in eukaryotes is known as mitosis, and leaves the daughter cell capable of dividing again. The corresponding sort of cell division in prokaryotes is known as binary fission. In another type of cell division present only in eukaryotes, called meiosis, a cell is permanently transformed into a gamete and cannot divide again until fertilization. Right before the parent cell splits, it undergoes DNA replication.

For simple unicellular organisms such as the amoeba, one cell division is equivalent to reproduction-- an entire new organism is created. On a larger scale, mitotic cell division can create progeny from multicellular organisms, such as plants that grow from cuttings. Cell division also enables a sexually reproducing organisms to develop from the one-celled zygote, which itself was produced by cell division from gametes. And after growth, cell division allows for continual construction and repair of the organism. A human being's body experiences about 10,000 trillion cell divisions in a lifetime.

The primary concern of cell division is the maintenance of the original cell's genome. Before division can occur, the genomic information which is stored in chromosomes must be replicated, and the duplicated genome separated cleanly between cells. A great deal of cellular infrastructure is involved in keeping genomic information consistent between "generations".

*Definition from http://en.wikipedia.org/wiki/Cell_division

Click here for slide show (Meiosis)

Click here for slide show (Mitosis)

CHAPTER 4: Chemical Composition of the Cell

2010-05-01T19:31:00.000-07:00

Hydrogen, oxygen, nitrogen, carbon, sulfur, and phosphorus normally makeup more
than 99% of the mass of living cells.

Ninety-nine percent of the molecules inside living cells are water molecules.
Cells normally contain more protein than DNA.
Homogenous polymers are non-informational.
All non-essential lipids can be generated from acetyl-CoA.
Like certain amino acids and unsaturated fatty acids, various inorganic elements are dietarily "essential".
Most all diseases in animals are manifestations of abnormalities in biomolecules, chemical reactions, or biochemical pathways.

Click here for slides

difference between seizures and epilepsy

2010-04-18T00:50:00.000-07:00

Seizures are a symptom of epilepsy. Epilepsy is the underlying tendency of the brain to produce a sudden burst of electrical energy that disrupts other brain functions. Having a single seizure does not necessarily mean a person has epilepsy. A number of factors, including high fever, severe head injury and lack of oxygen, can affect the brain enough to cause a single seizure. Epilepsy, on the other hand, is an underlying condition that affects the delicate systems that

govern how electrical energy behaves in the brain, making the brain susceptible to recurring seizures. While any seizure is cause for concern, having a seizure does not by itself mean a person has epilepsy. First seizures, febrile seizures, nonepileptic events, and eclampsia are examples of seizures that may not be associated with epilepsy.

First Seizures: Many people have a single seizure at some point in their lives. Often these seizures occur in reaction to anesthesia or a strong drug, but they also may be unprovoked, meaning that they occur without any obvious triggering factor. Unless the person has suffered brain damage or there is a family history of epilepsy or other neurological abnormalities, these single seizures usually are not followed by additional seizures. One recent study that followed patients for an average of 8 years found that only 33 percent of people have a second seizure within 4 years after an initial seizure. People who did not have a second seizure within that time remained seizure-free for the rest of the study.

Febrile Seizures: Sometimes a child will have a seizure during the course of an illness with a high fever. These seizures are called febrile seizures (febrile is derived from the Latin word for "fever") and can be very alarming to the parents and other caregivers. In the past, doctors usually prescribed a course of anticonvulsant drugs following a febrile seizure in the hope of preventing epilepsy. However, most children who have a febrile seizure do not develop epilepsy, and long-term use of anticonvulsant drugs in children may damage the developing brain or cause other detrimental side effects. Experts at a 1980 consensus conference coordinated by the National Institutes of Health concluded that preventive treatment after a febrile seizure is generally not warranted unless certain other conditions are present: a family history of epilepsy, signs of nervous system impairment prior to the seizure, or a relatively prolonged or complicated seizure.

Nonepileptic Events: Sometimes people appear to have seizures, even though their brains show no seizure activity. This type of phenomenon has various names, including nonepileptic events and pseudoseizures. Both of these terms essentially mean something that looks like a seizure but isn't one. Nonepileptic events that are psychological in origin may be referred to as psychogenic seizures. Psychogenic seizures may indicate dependence, a need for attention, avoidance of stressful situations, or specific psychiatric conditions. Some people with epilepsy have psychogenic seizures in addition to their epileptic seizures. Other people who have psychogenic seizures do not have epilepsy at all. Psychogenic seizures cannot be treated in the same way as epileptic seizures. Instead, they are often treated by mental health specialists. Other nonepileptic events may be caused by narcolepsy, Tourette syndrome, cardiac arrythmia, and other medical conditions with symptoms that resemble seizures.

Eclampsia: Eclampsia is a life-threatening condition that can develop in pregnant women. Its symptoms include sudden elevations of blood pressure and seizures. Pregnant women who develop unexpected seizures should be rushed to a hospital immediately. Eclampsia can be treated in a hospital setting and usually does not result in additional seizures or epilepsy once the pregnancy is over.

source: http://neurology.health-cares.net/epilepsy-seizures-difference.php

CHAPTER 3: Movement of Substances Across the Plasma Membrane

2010-04-10T23:06:00.000-07:00

The plasma membrane or cell membrane surrounds the cell contents in all types of cells. It is a multipurpose covering composed of phospholipids and proteins.

Apart from the plasma membrane, an eukaryotic cell also shows intracellular and subcellular membranes around its organelles and vacuoles. Such membranes are also found all over the cytoplasm as a network called endoplasmic reticulum. These membranes thus, compartmentalize the cell into discrete functional units. The plasma membrane and the subcellular membranes are involved in the flow of selected materials across the cell, as and when the cell needs them.

Click here for the slides